67 Dart 273 swap to 383
Just my 2 cents...
Go get a low mile wrecking yard 360.
Put a cam in it and a good 4bbl intake and headers
Swap in the 67 timing cover and cast iron water pump and accessory drives
Iirc the magnum 360s don't have the eccentric for the fuel pump so watch for that too
Everything basically bolts up.
Something about the pilot bushing that changed in the 60s so look into that. I think you can get a torque converter that has the 360 sized snout but will fit the 67 904
Saves 150 to 200 lbs and a **** tone of headache